Dump truck



March17, 1936. w LQWDEfQMILK Z,U34,306

DUMP TRUCK Filed March 2, 1935 2 sheets-sheet 1 INVENT OR.

ATTORNEY.

March 17, 1936. E, w, LOWDIERIMILK 2,934,306

DUMP TRUC K Filed March 2, 1935 2 sheets she et 2 um 'ulml Ell PatentedMar. 17, 1936 UNITED STATES ATENT OFFICE DUMZP TRUCK Elbert W.Lowdermilk, Denver, 0010. Application March 2, 1935, Serial No. 9,027

4 Claims.

This invention relates to a dump truck and has for its principal objectthe provision of a dump construction, which will elevate the dump bodyto an exceedingly high elevation; which can be operable from the usualtruck Winch; which will require a minimum of power to elevate a maximumload; which will eliminate all projecting posts, hoists, etc.; and whichwill rapidly raise and lower the body or lock the same in any desiredposition.

Another object of the invention is to so construct the device that aseries of different leverages will be employed; so that a minimum ofpower will be required to start a heavy load, carry it through the firstheavy lifting stages; and thence rapidly through the final lighterlifting stages.

A further object of the invention is to provide a winch operating dumpbody which will not interfere with the use of the winch for hoistingoperating derrick or other purposes.

Other objects and advantages reside in the detail construction of theinvention, which is designed for simplicity, economy, and efficiency.These will become more apparent from the following description.

In the following detailed description of the invention reference is. hadto the accompanying drawings which form a part hereof. Like numeralsrefer to like parts in all views of the drawings and throughout thedescription.

In the drawings:

Fig. 1 is a side elevation of the improved dump truck illustrating it inthe partially elevated position.

Fig. 2- is an enlarged fragmentary side elevation illustrating the bedstarting to elevate.

Fig. 3 is a longitudinal section through the preferred form of winchemployed with the invention.

Fig. 4 is a fragmentary side elevation illustrating the bed in the fullelevated position.

Fig. 5 is a similar view illustrating the bed in the down position.

Fig. 6 is a detail perspective view illustrating the cable connectionsto the winch.

In the drawings: a typical truck chassis is indicated at I!) supportedupon the usual wheels I and provided with the usual drivers cab I2,engine hood l3 and bed I4. The bed I4 is pivoted to the rear of thechassis l9 upon a suitable hinge bolt 49. At the rear of the cab I2 is awinch l5 which may be any of the usual truck winches, but is preferablyof a special design, as shown in Fig. 3.

The winch illustrated in Fig. 3 comprises a tubular winch shaft l6driven from suitable worm drive gears enclosed in a housing IT. The wormdrive may be connected with the engine drive shaft through a chain as isusual in truck winches. The winch shaft is supported in a bearing I8 atone extremity and in the winch housing IT at its other extremity andterminates in a fixed spool or nigger head 50.

Mounted upon the winch shaft are two side dumping spools I 9 and 20,positioned at each side of a main spool 2|. All of the spools arenormally free to rotate upon the winch shaft l6. A first sliding gear 22is mounted on the winch shaft within the spool l9, and a second slidinggear 23 is mounted on the winch shaft between the spools 20 and 2|. Thefirst gear 22 may be brought into mesh with an internal gear 24 on theinterior of the spool ill. The second gear 23 may be selectively broughtinto mesh with an internal gear 25 on the main spool 2| or an internalgear 26 on the side spool 20.

The two gears 22 and 23 may be moved axially by means of a slide rod 21which extends into the hollow shaft l6 and connects by means of suitablespider arms 28 with the gears. The spider arms 28 slide in longitudinalslots formed in the wall of the tubular winch shaft IS. The slide rod isoperated from an operating lever 29 which is connected to the slide rod21 and fulcrumed in a bracket 39 on the support of the bearing l8. It ispreferred to extend the operating lever 29 to a point within the reachof the operator in the cab I2.

It can be readily seen that as the operating lever 29 is swung inwardly(to the right in Fig. 3) it will cause the sliding gears 22 and 23 tolock the side spools l9 and 29 to the winch shaft Hi. When swungoutwardly, it will cause the sliding gear 23 to lock the main spool 2|to the winch shaft. When in between these two positions, none of thespools will be locked to the shaft, but will be free to rotate thereon.

The side spools 9 and 20 are formed with suitable brake drums 3| and 32against which brake bands 33 and 92 act. The main spool 2| is providedwith suitable brake drums 35 against which brake bands 39 act.

The dumping operation is accomplished by means of the side spools l9 and20. The dumping mechanism consists of a pair of similar toggle arms 3?hinged below and at each side of the forward extremity of the bed l4,and terminating in a horizontal roller shaft 38. A pair of sliding arms39 extend forwardly and downwardly from the roller shaft 38 at each sideof the chassis I. These sliding arms are formed with elongated slots 40in their forward extremities, through which guide bolts 4| pass. Thebolts 4| are permanently fixed to the chassis |0.

The roller shaft 38 extends across the chassis |0,-connecting theopposite pairs of levers 31 and 48. This shaft carries a series ofsheave wheels 42 between the arms 31 and a roller 43 at each extremitybetween each pair of arms 31 and 39. A jack shaft 5| extends laterallyacross the chassis ahead of the roller shaft 38 and carries a secondseries of sheave wheels 52. An equalizing pulley 45 is mounted below thewinch l5. An endless cable 44 is trained from each side spool of thewinch rearwardly about the sheaves 42, thence forwardly about thesheaves V 52 and around the equalizing pulley 53.

The side members of the chassis are formed with top track members 46,the rearward extremities of which are inclined to form an inclined track41. 'This track is so positioned that when the sliding arms 39 are attheir rearmost positions, with respect to the slots 4|], the rollers 43will be at the bottom of the inclined tracks 41. Beneath the forwardextremity of the bed I4 is a cable roller 48, which, when the bed isdown, rests upon the cables 44.

Let us assume that the bed I4 is in the horizontalposition of Fig. 5,and that it is desired to dump the contents thereof. The operator swingsthe operating lever 29 to the right so as to engage the winch with theside spools l9 and 20. He then starts to reel in the cable 44. The firsttightening of the cable acts to lift the sheave wheel 48 directl upwardand start the initial dumping movement of the bed, as shown in Fig. 2.The tightening cable then acts to draw the roller shaft 38 toward thewinch. This causes the rollers 43 to travel upwardly on the inclinedtracks 42 so as to continue the upward movement of the bed andstraighten the toggle of the arms 31 and 39. As the rollers moveforwardly, the sliding arms 39 will also move forwardly until theextremities of the guide slots 40 reach the guide bolts 4|. At thispoint, the rollers 43 will have reached the top of the inclined tracks41. From then on, the action is a simple toggle action between thelevers 31 and 39. The tightening cable will tend to straighten theselevers and.

force the bed upwardly to the position of Fig. 5.

The bed may then be locked in the elevated position by means of thebrake bands 33 and 34, the side spools can be released from the winch .1shaft, the winch clutch released and the truck started; The bed can thenbe lowered as desired by releasing the brake bands 33 and 34.

The brake bands can be operated in any suitable way, such as from brakelever shafts 5| and 52 operated from suitable brake levers convenient tothe driver.

The dumping mechanism can be operated from the ordinary truck-winch bysimply training the cable 44 over the ordinary winch spool. Thisnecessitates disconnecting the cable from the dumping mechanism when itis desired to use the winch for other purposes; With the winch of Fig.3, however, the center spool 2| can be used for the usual winch purposeswithout interfering with the use of the side spools for dumpingoperations.

If desired, space could be conserved by placing the winch spools belowthe drivers seat in the cab |2. Thus, enabling the entire chassis to beused for bed purposes. 7

It is desired to call particular attention to the fact that it is alwaysdifilcult to start the movement of a pair of closed toggle arms.Therefore it would require excessive power to cause the cable to pulldirectly upon the roller shaft 38 to obtain the initial lift. In thisinvention, this excessive power requirement is avoided, first, byallowing the tightening cable to lift directly on the front of the bed,through the roller 48; second, by allowing the toggle arms to slideforward while the rollers travel up the inclined tracks 41. After thisfirst movement is started, it is comparatively easy for the cable tostraighten the toggle arms for the final lift. By bringing the cableabout the two series of sheaves 42 and 52, a leverage is also obtainedto assist the raising of the bed.

The equalizing pulley 45 acts to equalize the strain in the cable 44 andto cause the cable to lift equally at both sides of the chassis. Itwould be practically impossible to obtain an equal lift at both sideswith two independent cables since it would be impossible to startreeling both of them simultaneously and. to retain them at equallengths.

While a specific form of the improvement has been described andillustrated herein, it is desired to be understood that the same may bevaried,

within the scope of the appended claims, without departing from thespirit of the invention. Having thus described the invention, what isclaimed and desired secured by Letters Patent 1. Means for dumping ahinged truck body comprising: a chassis; a body hinged at its rearextremity to said chassis; a first pair of toggle arms hinged to saidchassis; beneath the forward extremity of said body; a second pair oftoggle arms hinged to said first pair and extending upwardly therefromto a connection with said body; a winch supported on said chassis; acable connecting said winch with the hinge point between said arms so asto pull the latter to a straight position to elevate said body; rollerspositioned at the hinge points of said toggle arms and inclined planescarried by said chassis beneath said rollers to impart the initialmovement to said body as said cable tightens, said toggle armsbeingarranged to allow a limited preliminary movement for the actuation ofsaid rollers.

2. In a truck body having a chassis and a dumping body hinged adjacentthe rear extremity of said chassis; means for lifting the forwardextremity of said body comprising: a. first pair of toggle arms hingedto each side of the forward exrearward thereunder; a roller shaftextending between the rearward extremities of said arms; a cable wheelmounted on said roller shaft between said arms; a second pair of togglearms mounted at their rearward extremities on said roller shaft andextending normally forward therefrom; guide members secured to each sideof said chassis, said second pair of arms being slotted to pass oversaid guide members; a winch mounted on said chassis; a cable extendingrearwardly from said winch about said cable wheel and forwardly to aconnection with said chassis, said body normally resting upon said cablewhen in the lowered position.

3. In a truck body having a chassis and a dumping body hinged adjacentthe rear extremity of said chassis; means for lifting the forwardextremity of said body comprising: a first pair of toggle arms hingedto. each side of the forward extremity of said body and extendingnormally rearward thereunder; a roller shaft extending between therearward extremities of said arms; a cable wheel mounted on said rollershaft between said arms; a second pair of toggle arms mounted at theirrearward extremities on said roller shaft and extending normally forwardtherefrom; guide members secured to each side of said chassis, saidsecond pair of arms being slotted to pass over said guide members;rollers mounted on each extremity of said roller shaft; inclinedsurfaces on said chassis below said rollers, said surfaces beingpositioned so that as said rollers travel therealong, said slots willmove along said guide members; a winch mounted on said chassis; and acable extending from said winch to said cable wheel so as to draw saidroller shaft forwardly.

4. A dump truck construction comprising: a chassis; a dump body hingedadjacent the rear extremity of said chassis; a pair of toggle armshinged to and suspended from the forward extremity of said body at eachside thereof; a guide stud carried at each side of said body, the lowerarm of each pair of toggle arms being slotted to receive said stud; ashaft connecting the hinge points of said pairs of toggle arms; rollerscarried by said shaft; inclined members positioned immediately ahead ofsaid rollers; and cable means for drawing the hinge point of said toggleforwardly so that said rollers will travel upward on said inclinedmembers as the lower arms travel forward on said studs.

ELBERT W. LOWDERMILK.

